Omni-directional imaging and illumination assembly

ABSTRACT

In a first aspect, the present invention provides an omni-directional imaging assembly. In the preferred embodiment the assembly of the invention comprises a solid omni-directional lens comprising a vertical axis of symmetry; an upper surface, at least part of which is capable of reflecting rays that arrive from the inner side of the omni-directional lens; a transparent perimeter surface; a lower convex surface, at least part of which is capable of reflecting rays that arrive from the direction of the perimeter surface; and a transparent circular surface maintained in the lower convex surface around the vertical axis of symmetry. The light rays from a first 360 degrees, panoramic, scene are refracted by the transparent perimeter surface, are then reflected by the lower convex surface towards the upper surface, and then reflected by the upper surface towards the transparent circular surface, where they are refracted and exit the omni-directional lens. In a second aspect the omni-directional imaging assembly of the invention can be combined with an illumination source to simultaneously provide both omni-directional imaging and omni-directional illumination. Also described are embodiments of the invention that comprise image capturing devices, embodiments that enable simultaneous imaging of the first scene and a second scene, and embodiments that are adapted to the requirements of endoscopic imaging.

FIELD OF THE INVENTION

The present invention relates to the field of omni directional imagingand illumination. More specifically, it relates to optical structuresthat enable the coverage and illumination of a panoramic or nearlyspherical field of view, suitable for video or still imaging in bothwell-lit environments as well as dark environments.

BACKGROUND OF THE INVENTION

The use of imaging equipment has penetrated, over the years, into almostevery field and has become an essential aid for accomplishing a varietyof tasks. Imaging equipment is used in a wide range of security systems,to monitor sensitive locations and facilities, and to provide a reliableand cost-effective solution for perimeter security. An additional usefor imaging equipment is in the military, where image-based systems areused for reconnaissance gathering, enhanced situational awareness,automatic navigation and for many additional human-operated as well asautomated systems.

In the medical field imaging devices are also used; during endoscopicprocedures, for example, a surgical scope is inserted into body cavitiesfor imaging the inner body for diagnostic and surgical purposes.

Imaging devices are used in many additional fields, some commercial, andothers for private, home use, for purposes of entertainment, photographyand even baby monitoring.

Prior art techniques of imaging rely on the use of an image sensingdevice equipped with an optical lens. The prior art optical lenses aredesigned to cover a specific-sized field of view, and transmit thisfield of view to be captured by the image sensing device. While mostoptical lenses presented in the prior art provide the ability to capturea field of view limited in its aperture, a need exists to capture anunlimited field of view, or an omni-directional field of view, i.e. apanoramic (cylindrical) field of view or a nearly spherical field ofview.

An optical lens that covers an omni-directional field of view andenables the image sensing device to capture that omni-directional scenesimultaneously would provide significant improvement to imaging devices.The omni-directional scene that would be covered would enable constantawareness of the omni-directional scene. The advantages of such anoptical lens are obvious—security systems will have no “dead zones” andwill constantly cover and monitor the omni-directional scene. Medicalscopes will provide the surgeon with the ability to view the entireenvironment in which he operates and avoid the risk of injuring innerbody tissue or cause breach of blood vessels which were previouslyobscured from his view. Military systems will also benefit from theability to view an omni-directional scene and so will most systems basedon image sensing, whose performance is currently limited by the limitedaperture provided by their optical lenses.

Some techniques of panoramic imaging have been presented in prior art,and those make use of several image capture devices, each one aimed at adifferent sector limited in width, combined in a manner that all of themtogether, when properly aligned, cover a full 360 degrees field of view.Another prior art method for panoramic imaging relies on a single imagecapture device, rotated around a vertical axis. In this method the imagecapturing device covers a limited sector at any single moment, but whilecompleting a full rotation, it creates a sequence of images which arecombined together to a panoramic image. In this method it is impossibleto see simultaneously and in real-time the omni-directional scene.

The main disadvantage of the above mentioned prior art methods is theirrelative complexity. Some of the prior art methods necessitatemoving/rotating mechanisms, require frequent alignment and very oftenturn out to be maintenance-intensive.

A different prior art approach makes use of axis-symmetric reflectivesurfaces, used to reflect an omni-directional field of view towards asingle image-capture device. In this approach a circular image is formedon the focal plane array of the image capture device. The shape of theimage derives from the reflection of the surrounding field of view bythe reflective surface. The image shape and possible aberrations arecorrected by image processing techniques. A sub-group of the saidtechnique makes use of two reflective surfaces designed to doublyreflect the omni-directional field of view towards the image capturedevice. Such a design is described in U.S. Pat. No. 6,426,774. In thesaid patent, a convex axis-symmetric reflective surface reflects acylindrical field of view towards a flat reflective surface locatedcoaxially with it. A circular image is reflected from the convexaxis-symmetric surface towards the flat reflective surface and thenreflected towards an image capture device, which is located at theconcave side of the convex reflective surface, through a hole located atthe center of the axis-symmetric convex reflective surface.

Additional methods have been developed to achieve capture of an enlargedfield of view of an almost spherical scene. Such a design is describedin WO02/059676, the description of which, including reference citedtherein, is incorporated herein by reference in its entirety. In thesaid publication, two reflective surfaces are used, in both of which atransparent area is formed at the center to enable penetration of beamsoriginating at an additional scene, which is not covered by thereflective surfaces. As a result of the unique design, a nearlyspherical field of view is captured, comprising a cylindrical field ofview doubly reflected by the reflective surfaces towards the imagecapture device, and an additional field of view penetrating through thesaid transparent areas towards the image capture device. The saidtransparent areas may be fabricated either as transparent surfaces or asoptical lenses which enhance the properties of the additional scene.

The mentioned prior art techniques represent methods of acquiring alarge field of view, using optical structures which comprise severalseparate optical components.

In view of the deficiencies of the prior art, it would be desirable toprovide an optical lens that enables coverage of a panoramic or nearlyspherical field of view by utilizing a monolithic optical block, whichincorporates all refractive and reflective surfaces needed to acquirethe scene. As a result of the shape of such an optical block and itssurfaces, aberrations would be reduced to an acceptable level andgenerally there would be need of additional correction lenses along theoptical path, thus simplifying the optical design and structure andreducing production costs.

It is therefore an object of the present invention to provide such anoptical lens designed to cover a panoramic field of view.

It is another object of the present invention to provide an optical lensdesigned to cover a nearly spherical field of view.

It is yet another object of the present invention to provide methods ofilluminating the omni-directional scene that is to be imaged, using anoptical lens as both the omni-directional illumination distributor andas the optical element designed to collect the image of theomni-directional scene.

Additional objects of the invention would become apparent as thedescription proceeds.

SUMMARY OF THE INVENTION

In a first aspect, the present invention provides an omni-directionalimaging assembly. In the preferred embodiment the assembly of theinvention comprises a solid omni-directional lens which comprises:

-   -   (a) a vertical axis of symmetry;    -   (b) an upper surface, at least part of which is capable of        reflecting rays that arrive from the inner side of the        omni-directional lens;    -   (c) a transparent perimeter surface;    -   (d) a lower convex surface, at least part of which is capable of        reflecting rays that arrive from the direction of the perimeter        surface; and    -   (e) a transparent circular surface maintained in the lower        convex surface around the vertical axis of symmetry.

The light rays from a first 360 degrees, panoramic, scene are refractedby the transparent perimeter surface, are then reflected by the lowerconvex surface towards the upper surface, and then reflected by theupper surface towards the transparent circular surface, where they arerefracted and exit the omni-directional lens.

In one preferred embodiment of the omni-directional imaging assembly ofthe invention, at least a part of the upper surface of theomni-directional lens is coated with reflective material on its exteriorside to enable reflection of rays that arrive at the upper surface fromthe interior of the omni-directional lens. Alternatively oradditionally, at least a part of the lower convex surface of theomni-directional lens is coated with reflective material on its exteriorside to enable reflection of rays that arrive at that part of the lowerconvex surface from the direction of the perimeter surface. The uppersurface and/or the lower convex surface of the omni-directional lens canbe designed to enable reflection of rays that arrive at those surfaceswithout the use of a reflective coating by the use of total internalreflection.

In another embodiment, the omni-directional imaging assembly of theinvention can further comprise a second transparent circular areamaintained in the upper surface of the omni-directional lens around thevertical axis of symmetry. The second transparent circular area enablespenetration of rays from a second scene, which is at least partiallydifferent than the first scene, into the omni-directional lens. Raysfrom the second scene travel through the omni-directional lens, arerefracted by the transparent circular surface in the lower surface, andexit the omni-directional lens.

The omni-directional imaging assembly of this last embodiment canfurther comprise an optical structure located coaxially with theomni-directional lens and above its upper surface. This opticalstructure is designed to control and enhance optical qualities of thesecond scene, before rays originating in the second scene are refractedby the second transparent circular area. The optical structure can bedesigned to control the aperture of the second scene. The opticalstructure can comprise a plurality of optical elements.

The omni-directional imaging assembly of the invention can furthercomprise an image capture device. The image capture device is directedtowards the transparent circular surface in the lower surface of theomni-directional lens and its optical axis coincides with the verticalaxis of symmetry of the omni-directional lens. The image capture devicecan comprise a focusing lens.

The omni-directional imaging assembly may further comprise a connectorlocated between the omni-directional lens and the image capture device.The connector has a first edge and a second edge. Optical transparencyexists between the two edges, thereby allowing light which penetratesthe first edge to reach and exit through the second edge essentiallywithout distortion. The connector can be cylindrical in shape. The firstedge of the connector can be designed to be connected to theomni-directional lens and the second edge of the connector can bedesigned to be connected to the image capture device. The distancebetween the first edge of the connector and the second edge can bedesigned to allow optimal focus by the image capture device of the imagethat arrives from the direction of the omni-directional lens. Theconnector can be fabricated together with, and as a part of, theomni-directional lens as a unified optical block.

In a preferred embodiment of the invention the side edges of theconnector have a transparent volume allowing rays that arrive from thesecond edge to travel through the side edges, to exit through the firstedge, and to enter the omni-directional lens.

In a second aspect the omni-directional imaging assembly of theinvention can be combined with an illumination source to provideomni-directional illumination.

To accomplish the goal of providing omni-directional illumination, theomni-directional imaging assembly of the above mentioned embodiment ofthe invention can further comprise an illumination source locatedadjacent to the second edge of the connector. The illumination sourcetransmits illumination towards the transparent volume of the connector.The illumination rays travel through the transparent volume of theconnector, penetrate the omni-directional lens, and are distributedomni-directionally by the reflective and refractive surfaces of theomni-directional lens. In this way omni-directional illumination isprovided. In order to absorb stray light and preventing glare, the outersurface of the side of the connector can be blackened by a coating or bythe presence of a mechanical element.

The omni-directional imaging assembly of the invention can furthercomprise an illumination source located adjacent to the transparent areain the lower convex surface. This illumination source distributesillumination towards the interior of the omni-directional lens. The lensrefracts and reflects these illumination rays distributing themomni-directionally, thereby providing omni-directional illumination.

The illumination source in all embodiments of the invention can comprisea plurality of illumination sources and be capable of illumination atseveral different wavelengths. In all embodiments of the invention, thefabrication material and coating material of the omni-directional lensmust be suitable to distribute the spectral range of the illumination.

In some embodiments of the invention, the upper surface and/or the lowerconvex surface of the omni-directional lens can be described by morethan one geometrical curve.

An embodiment of the omni-directional imaging assembly of the inventionfurther comprises a hole extending from the upper surface of theomni-directional lens to the lower convex surface. The hole is aroundthe vertical axis of symmetry and is designed such that rays from thesecond scene travel through the hole to pass through theomni-directional lens. An optical element can be placed within the holeto control the quality of the image of the second scene. The outsidesurface of the optical element that is placed in the hole can be coatedwith black coating to absorb light and prevent glare. Additionally oralternatively, the surface of the hole can be coated with black coatingto absorb light and prevent glare. The hole can be cylindrical orconical in shape.

The omni-directional imaging assembly of the invention can furthercomprise cylindrical slots in the body of the omni-directional lensaround the axis of symmetry to absorb stray light and prevent glare. Theslots are formed in size and angle such as to not interfere with theoptical path of rays originating in scenes that should be covered by theomni-directional lens.

The omni-directional imaging assembly of the invention may furthercomprise a prism and an illumination source. The prism is locatedcoaxially with the omni-directional lens and the illumination source islocated to the side of and directed towards the prism. The prism isdesigned and positioned such as to transmit rays that arrive from thedirection of the omni-directional lens to the desired location, i.e. inmost instances to the image capture device, and to refract illuminationrays originating at the illumination source towards the omni-directionallens.

Another embodiment of the omni-directional imaging assembly of theinvention can further comprise an image capture device located above andadjacent to the upper surface. This image capture device is directedopposite to the omni-directional lens and is designed to cover anadditional scene, at least partially different from the first scene.

In yet another embodiment of the omni-directional imaging assembly ofthe invention, the omni-directional lens further comprises a hole to theside of the vertical axis of symmetry. This hole extends from the uppersurface to the lower surface of the lens and comprises a mechanicalchannel. The mechanical channel can be used to pass gases, liquids, ormechanical devices through the mechanical channel for cleaning theexterior of the omni-directional lens. The mechanical channel can alsobe used to pass surgical instruments through the omni-directional lens.

All the above and other characteristics and advantages of the inventionwill be further understood through the following illustrative andnon-limitative description of preferred embodiments thereof, withreference to the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

With specific reference now to the drawings in detail, it is stressedthat the particulars shown are by way of example and for purposes ofillustrative discussion of preferred embodiments of the presentinvention only. No attempt is made to show in the drawings structuraldetails of the invention in greater detail than is necessary forunderstanding of the invention. Details not shown in the figures arereadily understood by the skilled person who will easily appreciate howthe several forms of the invention may be carried out.

In the drawings:

FIG. 1 schematically describes an optical block that enables coverage ofa 360 degrees panoramic field of view, and the optical path of arepresentative light ray that travels through the optical block;

FIG. 2 schematically describes an incorporation of an image capturedevice and an optical block of the present invention, to provide animage of a 360 degrees panoramic field of view;

FIG. 3 schematically describes the general shape of the image that isacquired by an image capture device that is set to capture an image thatis created by the optical block of the present invention;

FIG. 4 schematically describes an optical block that enables coverage ofa 360 degrees panoramic field of view and an additional field of viewlocated above the panoramic field of view, and optical paths ofrepresentative light rays that travel through the optical block;

FIG. 5 schematically describes another possible design of an opticalblock of the present invention;

FIG. 6 schematically describes yet another possible design of an opticalblock of the present invention;

FIG. 7 schematically describes an additional possible design of anoptical block of the present invention;

FIG. 8 schematically describes a general shape of an optical block ofthe present invention, having a unique shape, suitable for smoothinsertion to body cavities, when implemented in medical endoscopicequipment;

FIG. 9 schematically describes an optical block of the present inventionthat enables omni-directional distribution of illumination,simultaneously with coverage of the omni-directional scene;

FIG. 10 schematically describes another possible method of incorporatingillumination sources with the optical block of the present invention;

FIG. 11 schematically describes an incorporation of an optical prism andan illumination source with the optical block of the present invention;

FIG. 12 schematically describes an incorporation of two image capturedevices with the optical block of the present invention to providecoverage of a nearly spherical field of view;

FIG. 13 schematically describes a design of the optical block of thepresent invention, incorporated with additional mechanical and opticalcomponents, for enhanced performance;

FIG. 14 schematically describes a generic method for incorporating asurgical channel within the optical block of the present invention; and

FIG. 15 schematically describes a method for protecting the outer upperoptical coating on the optical block.

DETAILED DESCRIPTION OF THE INVENTION

A first embodiment of the present invention provides a panoramic imagingassembly based on a unique optical block. The optical block is designedto collect light rays from a surrounding 360 degrees field of view andreflect them towards an image capture device located coaxially with it.The optical block is designed to have a transparent upper surface coatedwith reflective material on its exterior side, a perimeter transparentsurface and a lower convex transparent surface, which in someembodiments is coated with reflective material on its exterior side. Atransparent circular surface is maintained at the center of the lowerconvex transparent surface and is designed to allow light rays thatarrive from the direction of the upper surface to exit the optical blockand reach the image capture device. It is stressed that the exactstructure of the optical block and the exact formulas describing itscurves are subject to precise optical design. Proper optical design willpreserve maximum quality of the image that is refracted and reflected bythe optical block. It is further noted that the coverage range of thevertical field of view is also subject to the optical design and can becontrolled by the optical design. The optical design also dictates therequired distance between the optical block and the image capture deviceto ensure optimal focus by the image capture device on the image that isreflected from the optical block. Given the detailed descriptionprovided herein, the method of determining the values of the variousparameters needed to create the exact design and of determining theactual design for a given application would become apparent to thoseskilled in the art.

FIG. 1 is a schematic description of a monolithic optical block designedfor coverage of 360 degrees panoramic surroundings. The optical lens(block) (1) is fabricated as a single solid optical element comprising atransparent perimeter surface (2), a transparent upper surface (3), atransparent lower convex surface (4) and a circular transparent surface(5) located at the center of the lower convex surface (4). Thetransparent lower convex surface (4) is coated with reflective materialon its exterior side (in some embodiments), which is designed to reflectlight rays, which originate in a 360 degrees field of view (6)surrounding the axis of the lens, towards the upper surface (3). Theupper surface (3) is coated with reflective material on its exteriorside, which is designed to reflect light rays, which arrive from thedirection of the lower convex surface (4), towards the circulartransparent surface (5) and from there to an image capture device (notshown) located at the concave side of the lower convex surface (4). Itis stressed that the circular transparent surface (5) may be fabricatedwith a different geometry than that of the lower convex surface (4) forthe purpose of correcting some of the aberrations that may occur as aresult of the reflections and refractions of rays inside the lens (1).It is further stressed that the curvature of the upper surface (3) maybe designed in several ways to control the quality of the image that isreflected by the optical lens (1) and to aid in the ability of the imagecapture device to acquire an image with minimal aberrations and maximumfocus. Those skilled in the art will appreciate that the perimetersurface (2), the lower convex surface (4), the upper surface (3) and thetransparent circular surface (5) are all designed and determined withmutual consideration of each other's affects on the rays that penetratethe lens (1). Proper optical design will achieve both coverage of avertical field of view as required by the application, along withcontrol over the level of aberration and astigmatism of the image thatis reflected by the optical lens (1).

It is noted, that in some embodiments of the present invention, thelower surface (4) may be only partly coated with reflective material ornot coated at all, and still have the ability to reflect light rays fromthe perimeter scene towards the upper surface (3). The reflection may beachieved, by use of Snell's law of Total Internal Reflection in theoptical design.

Reference is now made to the optical paths of light rays originating inthe 360 degree field of view (6) surrounding the lens and located withinthe vertical field of view of the optical lens (1). A light ray (7)represents a group of light rays originating at the field of view (6)that is covered by the optical lens (1). The light ray (7) hits theperimeter refractive surface (2) at a first point (8) where it isrefracted and penetrates the optical lens (1). It then travels throughthe optical lens (1) and hits the lower surface (4) at a second point(9), where it is reflected towards the upper surface (3). The reflectionat lower surface (4) may be achieved either by coating the surface withreflective coating from its exterior or as a result of a Total InternalReflection effect. After hitting the lower surface (4) at the secondpoint (9), the first light ray (7) travels through the optical lens (1)and hits the upper surface (3) at a third point (10). When hitting theupper surface (3), the first light ray (7) is reflected towards thecircular transparent area (5), and hits the circular area (5) at afourth point (11), where it is refracted and exits the lens towards theimage capture device (not shown). The reflection of the ray from theupper surface (3) results from the existence of the reflective coatingon the exterior of the upper surface (3), or in some cases, as an effectof Total Internal Reflection. Similar paths can be described inreference to any other light ray originating within the field of view(6), which is covered by the lens (1). It is stressed that each of thelight rays originating from a different angle will hit different pointsof the aspheric optical lens, and will naturally have a differentoptical path.

FIG. 2 illustrates an entire imaging assembly, which utilizes theoptical block described in FIG. 1, to enable the capture of a 360degrees panoramic image. The imaging assembly comprises the optical lens(block) (1) and an image capture device (12). The image capture device(12) is directed towards the transparent circular surface (5), designedto capture the image that is doubly reflected from the upper surface (3)and refracted by the transparent surface (5). The optical axis of theimage capture device (12) preferably coincides with the axis of symmetryof the axis-symmetric optical lens (1). The distance between the imagecapture device (12) and the optical lens (1) is determined according tothe parameters of the optical design, with the purpose of ensuringmaximum focus of the image that arrives from the direction of theoptical lens (1) by the image capture device (12). To ensure a fixeddistance between the image capture device (12) and the optical lens (1),the lens (1) may be fabricated together with an attachment area (13),designed for direct mounting on the image capture device (12). In somecases, when a larger distance is required between the lens (1) and theimage capture device (12), a connector (not shown) may be incorporatedbetween the two said elements, connected at one end to the attachmentarea (13) of the lens (1) and at its second end to the image capturedevice (12). It is stressed that the length of the connector is designedin accordance with the optical design, to ensure optimal focus by theimage capture device (12) on the image that arrives from the directionof the lens (1). It is further stressed that the connector may befabricated as a continuation of the optical block, thus forming a singlemonolithic optical structure designed for direct mount on an imagecapture device (12). The image capture device (12) is preferablyequipped with its own focusing lens (14), which is set to focus theimage that should be captured by the image capture device (12). Thoseskilled in the art will appreciate that the focusing lens is chosen andadjusted in accordance with the distance between the image capturedevice (12) and the optical block (1), and according to thespecifications of the optical design. As previously noted, the distancebetween the image capture device (12) and the optical block (1) isdetermined by the optical design to ensure both optimal focus of theimage and preferably that the entire image that is reflected by theoptical block (1) and no more than that image, is captured by the imagecapture device (12), thus allowing optimal image resolution. For someapplications, which may require improved image quality, additionallenses (not shown) may be incorporated in between the focusing lens (14)and the optical block (1), designed to correct astigmatism of the imageprior to its capture by the image capture device (12). It is stressed,however, that proper optical design of the optical block (lens) (1) willreduce such astigmatism to a tolerable level suitable for mostapplications, and that generally additional optical elements, other thanthe optical block (lens) (1) and the focusing lens (14), are notrequired. The assembly as described herein will result in acquiring animage of a circular shape, which is actually the reflection of thepanoramic surroundings, as further described in reference to FIG. 3.

FIG. 3 is a schematic description of the shape of the image that isacquired by the image capture device described hereinabove. As describedwith reference to FIG. 2, the image capture device captures an image,which is the reflection of the panoramic scene. In FIG. 3, an image (15)is acquired by the image capture device. The image (15) contains a firstarea (16), which is the reflection of the panoramic view and a secondarea (17) which is the reflection of the image capture device itself.Every light ray, which originates in the panoramic field of viewsurrounding the lens (1) at an elevation angle which is covered by theoptical block (1), will appear in the first area (16) of the image (15).It is stressed that the image shape as indicated, describes an image asit is acquired by the image capture device in the preferable case inwhich the lens of the image capture device is set to capture all of, andno more than, the reflection and the reflection appears at the center ofthe image. The circular shape of the image, although suitable for someneeds, may be considered unsuitable for standard viewing. Therefore theimage is usually corrected by image processing software, designedspecifically according to the parameters of the optical block. Use ofthe software corrects the image shape and transforms it to anothershape, preferably rectangular, more suitable for viewing. It is stressedthat by using the imaging assembly described by FIG. 2, the centralsector (17) of the image (15) will comprise the reflection of the imagecapture device. Since this area of the image is actually “wasted”,advanced optical designs may be used such that section (17) comprises animage of a second scene, at least partially different from the panoramicscene that appears in the outer sector (16) of the image. An example ofsuch an advanced design is described hereinbelow with reference to anembodiment of the present invention in FIG. 4.

Another preferred embodiment of the present invention, shown in FIG. 4,provides an imaging assembly capable of capturing a first scene of 360degrees panoramic surroundings and a second scene, located at leastpartially above the first scene. The image capture is achieved using aunique optical structure and a single image capture device. The opticalstructure has several possible designs as will be described withreference to the figure. Those skilled in the art will appreciate thatthe exact structure and the exact formulas describing the curves andoptical properties of the surfaces of the optical structure of thisembodiment are subject to precise optical design. Proper optical designwill preserve maximum quality of the image that is acquired by the imagecapture device. It is further noted that the coverage ranges of thedifferent scenes are also subject to the optical design and can becontrolled by the optical design. Optical design also dictates therequired distance between the optical block and the image capture deviceto ensure optimal focus by the image capture device on the image thatarrives from the direction of the optical structure.

FIG. 4 is a schematic description showing one embodiment of a design ofan optical lens (18) designed for simultaneous coverage of a first scene(19) comprising a 360 degrees panoramic surroundings and a second scene(20) which is at least partially above the first scene. The opticalstructure comprises a single optical element (lens) (18). The opticalblock (lens) (18) comprises a transparent perimeter surface (27), atransparent upper surface (32), a transparent lower convex surface (21),a transparent circular surface (22) located at the center of thetransparent lower convex surface (21) and a transparent area (23)located at the center of the transparent upper surface (32).

The lower convex surface (21) is coated, in some embodiments, withreflective material on its exterior side and is designed to reflectrays, which originate in a 360 degree field of view surrounding thelens, towards the upper surface (32). The upper surface (32) is coated,in some embodiments, with reflective material on its exterior side andis designed to reflect rays, which arrive from the direction of thelower convex surface (21), towards the transparent circular surface (22)located at the center of the lower surface (21) and from there to animage capture device (not shown) located at the concave side of theoptical lens (18). It is stressed that at least an area (22) of lowersurface (21) should be transparent to enable rays to exits the block andreach the image capture device. It is further stressed that the uppersurface (32) is not coated entirely with reflective material and atransparent area (23) is maintained in the upper surface (32), allowinglight rays from the second scene (20) to penetrate the optical block(18) through said transparent area (23) and exit through said circulartransparent surface (22). The geometry of the transparent area (23) maybe different than that of the upper surface (32) and its shape may bedesigned to control the size of the upper sector (20) which is covered.It is also possible to make use of an additional optical structure (24)which is placed above the transparent area (23) and coaxially with thevertical axis of symmetry of the optical block (18). The opticalstructure (24) is preferably fabricated in a size that enables exactplacement and fastening to the optical block (18). The additionaloptical structure (24), when properly designed, enables control over thesize and optical qualities of second scene (20) that is covered. Theadditional optical structure (24) may be comprised of several separateoptical elements, however, for the purpose of brevity and clarity; it isreferred to as a single element.

Reference is now made to the optical paths of light rays originating inthe two scenes, which are covered by the optical block (18).

A first light ray (25) represents a group of light rays originating atthe panoramic scene (19). A second light ray (26) represents a group oflight rays originating at the second scene (20). The first light ray(25) hits the perimeter refractive surface (27) at a first point (28),and penetrates the optical block (18). The ray (25) then travels throughthe optical block (18) and hits the lower surface (21) at a second point(29), where it is reflected towards the upper surface (32). The ray (25)then hits the upper surface (32) at a third point (30) and it is thenreflected towards the circular transparent surface (22) hitting it at afourth point (31) where it is refracted and exits the lens (18).

Similar paths can be described with reference to any other light raythat originates within the first scene (19). The second light ray (26)hits the additional optical structure (24) and travels through it. Theray (26) may be refracted several times, should the additional opticalstructure (24) be comprised of several separate optical elements. Afterexiting the additional optical structure (24), the ray (26) travelstowards the transparent area (23). The ray (26) then hits thetransparent area (23), where it is refracted and enters into the opticalblock (18). The ray then travels through the optical block (18) until ithits the transparent circular surface (22) where it is refracted againand exits the optical block (18). As previously indicated, theadditional optical structure (24) is designed to control the size andoptical qualities of the second scene that will be covered. Theadditional optical structure (24) may be comprised of several separateoptical elements to compensate any aberrations that may be generatedalong the optical path of light rays that originate at the second scene.It is stressed that the optical path within the additional opticalstructure (24) is to be considered only if such optical structure (24)is indeed implemented. It is stressed that the transparent area (23) maybe fabricated by several methods. A first method is by forming only apartial reflective coating over the transparent upper surface (32),leaving an area around the vertical axis of symmetry of the opticalblock uncoated, and thus allowing light rays to penetrate the opticalblock. Another way of fabrication of the transparent area (23) is toproduce a refractive surface with different geometry than that of thetransparent upper surface by imposing a different curvature on an areaaround the vertical axis of symmetry of the optical block. This willcause the transparent area to have different refraction qualities. Athird method is by forming a hole, having a certain diameter, along thevertical axis of symmetry of the optical block to allow light rays topass freely through said hole. However, it should be appreciated thateach method will necessitate a different optical design.

The combination of an image capture device with the optical block (18)to achieve capture of the two scenes (simultaneously) may beaccomplished as demonstrated with reference to FIG. 2.

FIG. 5 is a schematic description of an embodiment of a solid opticallens (33) according to the present invention, in which the upper andlower surfaces are described by a plurality of geometric curves. Theupper surface of the lens (33) has a first area (35), described by afirst geometric curve, and a second area (36) described by a secondgeometric curve. The lower surface of the lens (33) has a first area(34) described by a first geometric curve, a second area (37) describedby a second geometric curve and a third area (38) described by a thirdgeometric curve. Each of the mentioned areas performs a differentoptical “task”, and therefore may be designed to have a differentgeometric shape, such that would enable it to optimally perform itsrespective optical task. Reference is now made to the different opticaltasks of each of the described areas. The first area (34) in the lowersurface is designed to reflect light rays from the panoramic perimetertowards the first area (35) of the upper surface. The first area (35) ofthe upper surface is designed to reflect these rays towards the secondarea (37) in the lower surface. The second area (37) in the lowersurface is designed to refract these rays, and enable them to exit thelens (33) and be captured by an image capture device (not shown). Thesecond upper surface (36) is designed to refract rays from a scene,which is different than the panoramic scene. These rays should travelthrough the lens (33) and reach the third area (38) in the lowersurface. The third area (38) in the lower surface is designed to refractthese rays and enable them to exit the lens (33) and be captured by thesame image capture device that captures the panoramic scene. Thespecific design of the curves of the surfaces directs the rays of thedifferent scenes to occupy different areas of the focal plane array,where the image is formed.

Due to the complexity of the optical paths, and the need to optimallyreflect, refract and capture rays that originate in different scenes,the use of multiple geometric curves to form the different surfaces ofthe lens (33) aids in the correction of aberration, astigmatism or otherdegradation in the image quality as well as in directing the rays to thefocal plane array as required. Such an embodiment may reduce the needfor using additional external lenses.

FIG. 6 schematically describes an additional embodiment of the opticallens of the present invention. In FIG. 6, the lens (39) is fabricatedwith a hole, preferably conically shaped, located along its central axisof symmetry, extending from its upper surface (41) to its lower surface.Inside the hole there is placed an additional optical structure (40)that is designed to refract rays from a scene located above the opticallens (39), a scene which is different from the panoramic scene reflectedby the lens (39). The additional optical structure (40) may be comprisedof multiple optical elements that would provide optimal opticalperformance. The shape of the additional optical structure (40) ispreferably such that it can be fastened into the hole in the lens (39)and totally adjacent to the upper surface (41) of the lens (39).According to this design, the reflective coating of the upper surface(41) may be on the upper surface itself or on the area of the additionaloptical element (40) that is to be adjacent to the upper surface (41). Afirst light ray (42) represents a light ray originating in the panoramicscene, traveling through the optical lens (39). A second light ray (43)represents a ray originating in an additional scene, located above thepanoramic scene.

FIG. 7 schematically describes an additional embodiment of the lens ofthe present invention. According to the present figure, the lens (44)has a perimeter surface (45) described by a negative curve. Anadditional optical element (50) is used to refract rays from a scenelocated above the lens (44) and above the panoramic scene covered by thelens (44). A first light ray (46) represents a ray originating in anupper scene covered by the additional optical element (50). A secondlight ray (47) represents a ray originating in the panoramic scenecovered by the lens (44). The second light ray (47), as well as anyother ray originating in the panoramic scene that is covered by the lens(44), will penetrate the lens (44) through the perimeter surface (45),will then be reflected by the lower reflective surface (48) of the lenstowards the upper surface (49). The rays will then be reflected by theupper surface (49) towards the transparent area (51) in the lowersurface of the lens (44) and will exit the lens. A transparent area (52)is maintained in the upper surface to enable rays from the upper scene,which are refracted by the additional optical element (50), to enter thelens (44), travel through it and exit through the transparent area (51)in the lower surface.

During medical endoscopy procedures, the surgeon is provided with meansto see inside the body for purposes of diagnosis or surgery. Endoscopicprocedures are known to suffer from the relatively narrow field of viewprovided by prior art endoscopic equipment. The lens provided by thepresent invention, can be implemented as an optical head of a medicalscope to enable the coverage of an omni-directional field of view, andprovide the surgeon with enhanced orientation and maneuverability.Implementation of the lens of the invention as an optical head of amedical scope would require it to be shaped in a manner that wouldenable smooth insertion into body cavities, and minimal danger tointernal organs when coming in contact with them. FIG. 8 describesschematically the general shape of one embodiment of the lens of theinvention for use with an endoscope. In FIG. 8, the lens (53) consistsof all of the surfaces shown in previous figures—the perimeter surface(54), the lower surface (55), the upper surface (56), and optionaladditional optical elements (57) designed to cover a scene differentthan the panoramic scene. The use of reflective surfaces has beendemonstrated in reference to the pervious figures; therefore, it willnot be elaborated in respect to the present figure. The design of thelens (53) in FIG. 8 must take two factors into consideration: the firstand most crucial factor is a design that achieves the desired field ofview and optical quality, and the second factor is the “ergonomic”shape.

Another aspect of the present invention refers to the incorporation ofan illumination source with the omni-directional lens of the presentinvention. It will be realized that in some cases the environment inwhich the imaging is performed is either poorly lit or completely dark.One example of such a situation is inner-body imaging during medicalendoscopy. Since it is crucial for the surgeon to see clearly theenvironment in which he operates, it is desired to provide illuminationthat would light the scene and enable clear imaging. When using anomni-directional lens, the illumination should be distributedomni-directionally to the entire scene that is to be imaged.

The present invention provides a method of illuminating theomni-directional scene by using the lens itself as an illuminationdistributor, as will be described hereinbelow.

FIG. 9 schematically describes the incorporation of an illuminationsource with the omni-directional lens of the present invention. In thisfigure the omni-directional lens (58) has an illumination conductor area(59). The illumination conductor area can be either fabricated togetherand as part of the monolithic structure of the lens, or can be connectedto the bottom edges of the lens (68). An illumination source (60) isattached to the illation conductor area (59), so that illuminationdistributed by the illumination source, penetrates the illuminationconductor are (59), travels through it, and reaches the body of the lens(58). The illumination is then distributed trough the body of the lensomni-directionally. In some cases there may be “stray” light rays thatwill be reflected towards the image capture device, causing glare inparts of the image. To avoid glare, it is possible to fabricatecylindrical or conical slots (61) around the central axis of symmetry ofthe lens. The slots should be positioned so that they would not block,or interfere with the optical path of light rays that originate at theperimeter scene or at the upper scene. The slots (61) will, however,block illumination rays from entering the optical path that leads to theimage capture device. It is also important to avoid stray illuminationrays from exiting through the outer surface (62) of the interior walldefining conductor area (59), since those rays might also cause glare inthe image captured by the image capture device. To avoid such an effect,it is possible to coat the outer surface (62) with a dark coating, or touse some kind of mechanical structure that would separate the imagecapture device from the possible effects of stray illumination.

FIG. 10 schematically describes another embodiment of theomni-directional lens of the present invention incorporatingillumination sources. As shown in FIG. 10, the lower surface (63) of theomni-directional lens (64) is not coated with reflective material. Thereflection of light rays, which originate in the panoramic scene, by thelower surface, even though no reflective coating is implemented, isachieved according to Snell's Law of Total Internal Reflection. Theabsence of reflective material on the lower surface (63) enablesincorporation of illumination sources (65) directly under the lowersurface (63), where illumination can pass freely through the lowersurface (63) and penetrate the body of the lens (64) and from there bedistributed omni-directionally into the scene surrounding the lens. Toavoid stray illumination effects, such as that caused by illuminationrays arriving at the image capture device and creating glare, it ispossible to incorporate a conical structure (66) which preferably hasblackened outer edges (67). In the present figure, is also shown how theconical structure (66) is used for two purposes. The first purpose, asdescribed above, is to isolate the illumination sources from the centraloptical channel and avoid glare. The second purpose is to use theconical structure (66) as an optical channel that is used to pass lightray from the upper scene through the lens. The rays from the upper sceneare routed to the optical channel of the conical structure (66) by anupper optical structure (68). It is stressed that the upper opticalstructure (68) and the conical structure (66) may be fabricated as asingle component, and for that purpose a hole may be fabricated in theomni-directional lens (64), through which, the said optical componentcan be inserted.

FIG. 11 schematically describes an embodiment of the present inventionincorporating an illumination source and an optical prism to achievesimultaneously omni-directional imaging and omni-directionalillumination. In the present figure, the omni-directional lens (69) ofthe present invention is located coaxially with an image capture device(70). In between the omni-directional lens (69) and the image capturedevice (70) there is positioned an optical prism (71), which hasdifferent optical effects on light rays that arrive at it from differentangles. At one side of the prism (71) there is positioned anillumination source (72), directed to illuminate that side of the prism.Reference is now made to optical paths of rays that travel through theprism (71). A first ray (73) represents a ray that originates in thepanoramic scene which is covered by the omni-directional lens (69). Asecond ray (74) represents a ray that originates in an additional scene,located above the omni-directional lens (69). The first ray (73) and thesecond ray (74) travel through the omni-directional lens (69) in asimilar way to that previously described with respect to FIG. 4. Thefirst ray (73) and second ray (74) exit the omni-directional lens (69)through the transparent area in the lower surface (75). These rays thentravel towards the optical prism (71). The angle at which these raysmeet the prism (71) and the qualities of the prism (71) result incomplete transmittance of these rays through the prism (71) and towardsthe image capture device (70). The same path and optical effects can bedescribed in relation to any other ray that originates in the panoramicscene or the upper scene, which are covered by the omni-directional lens(69). A third ray (76) represents a ray that originates at theillumination source (72). The illumination ray (76) hits the prism (71)and is refracted upwards, towards the omni-directional lens (69). Theangle in which the illumination ray (76) meet the prism (71) and theproperties of the prism (69) result in the refraction of theillumination towards the direction of the omni-directional lens (69).The illumination ray (76) penetrates the omni-directional lens (69)through the transparent area in the lower surface (75) of the lens. Someillumination rays will then hit the upper reflective surface (77) of thelens, will be reflected by it towards the lower reflective surface (78),and will be reflected from there to the perimeter surface (79) and willilluminate the surrounding scene. Additional illumination rays (81) willilluminate the upper scene after traveling through the lens (69) andexiting through the optical element (82) designed to cover the upperscene. It is stressed that the shape, location and optical effects ofthe prism (71) as demonstrated in this figure are purely schematic.Those skilled in the art would be able to design a prism suitable forperformance of the task described herein. Furthermore, the mechanicalattachment of the prism to the assembly may be performed in numerousmethods within the scope of those skilled in the art.

FIG. 12 schematically describes the incorporation of two image capturedevices to enable capture of two different scenes. A first image capturedevice (83) is directed towards an omni-directional lens (84) of thepresent invention. The omni-directional lens (84) and the first imagecapture device (83) are preferably coaxial. The omni-directional lens(84) provides coverage of a panoramic scene located around it. A firstray (85) represents a ray that originates in the panoramic scene,penetrates the lens (84), is reflected and refracted by the lens (84)and captured by the first image capture device (83). A second imagecapture device (86) is positioned above, and preferably adjacent to theupper surface (87) of the lens (84). The second image capture device(86) is designed to capture an additional scene, located above thepanoramic scene that is captured by the first image capture device (83).A second ray (88) represents a ray that originates at the additional,upper, scene and is directly captured by the second image capture device(86). The second image capture device (86) may be equipped withadditional optical lenses that enlarge the aperture of the field of viewthat it covers. It is stressed that the second image capture device (87)requires a power source as well as a method to transfer the image thatit acquires to the user. For these purposes, the second image capturedevice may either have wires that are connected to it for supplying thepower and transmitting the image, or it may comprise an internal powersupply and a means of wireless transmission of the image If wires areimplemented, they can be connected to the image capture device (86)through a hole (not shown) in the omni-directional lens or bypass thelens (84) from its exterior. In either of these embodiments the wireswould cause an obstruction of a part of the scene.

FIG. 13 schematically describes an additional embodiment of theomni-directional imaging assembly of the present invention. Theomni-directional lens (89) shown in FIG. 13 is fabricated havingmonolithic edges (90) which are a continuation of the monolithicstructure of the lens (89), meaning the edges (90) are fabricated as asingle unified unit with the lens (89). The edges (90) can be used as anillumination conductor, as was described in reference to FIG. 9. Towardthe inner side of the edges (90) there is inserted a mechanicalstructure (91), preferably adjacent to the edges. The mechanicalstructure (91) may be equipped with rod lenses (92) which may have theoptical purpose of routing the image to a relatively distant focal planearray and/or correcting aberrations, astigmatism, or other opticaldeficiencies of the image. The embodiment described in FIG. 13 may beapplicable to a wide variety of applications, including rigid endoscopy,where the lens structure (89) may be designed to be placed on anexisting rigid scope, to provide for both enlarged aperture coverage,and also isolate the scope itself from the inner-body environment, toreduce the exposure of the scope to contaminants. It this case, it isalso possible that the lens (89) may be a disposable component.

FIG. 14 schematically describes an implementation of theomni-directional imaging assembly of the present invention, to medicalendo-surgery applications. In FIG. 13 demonstrated an embodiment of theomni-directional lens that can be used to view the inner body andprovide diagnostic capability only. Sometimes there is, however, a needto perform surgery in the same procedure. The embodiment shown in FIG.14 incorporates a surgical channel in the imaging system that enablessurgical operations to be conducted, while enjoying the benefit of theomni-directional imaging assembly of the present invention. In thepresent figure the omni-directional lens (93) has a hole in one area,extending through the lens from the upper surface (94) to the lowersurface (95). Through the hole passes a channel (96) through which it ispossible to pass surgical tools, liquids or gases as required by thesurgical procedure that is performed. It is stressed that the design ofthe surgical channel itself has been presented in prior art, thereforethe operation of the surgical tools, and the inner structure of thesurgical channel is not elaborated herein. It is further stressed thatmore than one surgical channel may be incorporated, and several holesmay be made in the lens (93) through which several surgical channelswould be able to pass. However, it is important to note that eachsurgical channel that passes through the lens will cause an obstructionto the panoramic field of view that is supposed to be covered by thelens. Such obstruction may be regarded as negligible, since the surgeryitself is to be done on the “front” field of view, which is covered bythe additional optical element (97), whose performance is notcompromised by the presence of the surgical channel. The surgicalchannel may also be used for passing gases, liquids, or mechanicaldevices through the lens to clean its exterior surface which may becomeobscured during a surgical procedure.

FIG. 15 schematically describes a method of protecting the coating ofthe upper surface of the omni-directional lens of the present invention.In this figure, the upper surface (98) of the omni-directional lens (99)is completely coated with reflective material on its exterior side.Exposure of the reflective coating to environmental conditions for along period of time can result in degradation of its performance causedby cracking and peeling of the coating and the formation of bacteria onit. It is therefore desired to provide a shield that would protect thecoating from the surrounding environment. In FIG. 15 is shown a shield(100) that is placed on the concave upper surface (99), preferablyadjacent to the upper surface. The reflective coating may be on

1. An omni-directional imaging assembly comprising a solid omni-directional lens said omni-directional lens comprising: (a) a vertical axis of symmetry, (b) an upper surface, at least part of which is capable of reflecting rays that arrive from the inner side of the omni-directional lens; (c) a transparent perimeter surface; (d) a lower convex surface, at least part of which is capable of reflecting rays that arrive from the direction of said perimeter surface; (e) a transparent circular surface maintained in said lower convex surface around said vertical axis of symmetry; wherein light rays from a first 360 degrees, panoramic, scene are refracted by said transparent perimeter surface, are then reflected by said lower convex surface towards said upper surface, and then reflected by said upper surface towards said transparent circular surface, then refracted and exit said omni-directional lens.
 2. An omni-directional imaging assembly according to claim 1, wherein at least a part of the upper surface of the omni-directional lens is coated with reflective material on its exterior side to enable reflection of rays that arrive at said upper surface from the interior of said omni-directional lens.
 3. An omni-directional imaging assembly according to claim 1, wherein at least a part of the lower convex surface of the omni-directional lens is coated with reflective material on its exterior side to enable reflection of rays that arrive at said part of said lower convex surface from the direction of the perimeter surface.
 4. An omni-directional imaging assembly according to claim 1, wherein the upper surface and/or the lower convex surface of said omni-directional lens are designed to enable Total Internal Reflection of rays that arrive at said surfaces, without the use of a reflective coating.
 5. An omni-directional imaging assembly according to claim 1, further comprising a second transparent circular area maintained in the upper surface of the omni-directional lens around the vertical axis of symmetry; said second transparent circular area enabling penetration of rays from a second scene, at least partially different than the first scene, into said omni-directional lens, wherein rays from said second scene travel through said omni-directional lens, are refracted by the transparent circular surface in the lower surface, and exit said omni-directional lens.
 6. An omni-directional imaging assembly according to claim 5, further comprising an optical structure located coaxially with the omni-directional lens and above the upper surface of said lens; said optical structure being designed to control and enhance optical qualities of the second scene, before rays originating in said second scene are refracted by the second transparent circular area.
 7. An omni-directional imaging assembly according to claim 6, wherein the optical structure is designed to control the aperture of the second scene.
 8. An omni-directional imaging assembly according to claim 6, wherein the optical structure comprises a plurality of optical elements.
 9. An omni-directional imaging assembly according to claim 1, further comprising an image capture device, directed towards the transparent circular surface in the lower surface of the omni-directional lens and having its optical axis coinciding with the vertical axis of symmetry of said omni-directional lens.
 10. An omni-directional imaging assembly according to claim 9, wherein the image capture device comprises a focusing lens.
 11. An omni-directional imaging assembly according to claim 9, further comprising a connector located between the omni-directional lens and the image capture device, said connector having a first edge and a second edge, wherein optical transparency exists between said first edge and said second edge, allowing light penetrating said first edge to reach and exit through said second edge essentially without distortion.
 12. An omni-directional imaging assembly according to claim 11, wherein the connector is cylindrical in shape.
 13. An omni-directional imaging assembly according to claim 11, wherein the first edge of the connector is designed to be connected to the omni-directional lens.
 14. An omni-directional imaging assembly according to claim 11, wherein the second edge of the connector is designed to be connected to the image capture device.
 15. An omni-directional imaging assembly according to claim 11, wherein the distance between the first edge of the connector and the second edge is designed to allow optimal focus by the image capture device of the image that arrives from the direction of the omni-directional lens.
 16. An omni-directional imaging assembly according to claim 11, wherein the connector is fabricated together with, and as a part of, the omni-directional lens as a unified optical block.
 17. An omni-directional imaging assembly according to claim 11, wherein the side edges of the connector have a transparent volume allowing rays that arrive from the second edge to travel through said side edges, to exit through the first edge, and to enter the omni-directional lens.
 18. An omni-directional imaging assembly according to claim 17, further comprising an illumination source located adjacent to the second edge of the connector, said illumination source transmitting illumination towards the transparent volume of said connector, wherein illumination rays travel through said transparent volume of said connector, penetrate the omni-directional lens, and are distributed omni-directionally by the reflective and refractive surfaces of said omni-directional lens, thereby providing omni-directional illumination.
 19. An omni-directional imaging assembly according to claim 11, wherein the outer surface of the side of the connector is blackened by a coating or by the presence of a mechanical element, thereby absorbing light and preventing glare.
 20. An omni-directional imaging assembly according to claim 4, further comprising an illumination source located adjacent to the transparent area in the lower convex surface, said illumination source distributing illumination towards the interior of the omni-directional lens, which refracts and reflects said illumination rays distributing them omni-directionally, thereby providing omni-directional illumination.
 21. An omni-directional imaging assembly according to 18, wherein the illumination source comprises a plurality of illumination sources.
 22. An omni-directional imaging assembly according to claim 21, wherein the illumination source is capable of illumination at several different wavelengths.
 23. An omni-directional imaging assembly according to claim 18, wherein the fabrication material and coating material of the omni-directional lens are suitable to distribute the spectral range of the illumination.
 24. An omni-directional imaging assembly according to claim 1, wherein the upper surface of the omni-directional lens can be described by more than one geometrical curve.
 25. An omni-directional imaging assembly according to claim 1, wherein the lower convex surface of the omni-directional lens can be described by more that one geometrical curve.
 26. An omni-directional imaging assembly according to claim 5, further comprising a hole extending from the upper surface of the omni-directional lens to the lower convex surface around the vertical axis of symmetry, wherein said hole is designed such that rays from the second scene travel through said hole to pass through said omni-directional lens.
 27. An omni-directional imaging assembly according to claim 26, further comprising an optical element placed within the hole, wherein said optical element is designed to control the quality of the image of the second scene.
 28. An omni-directional imaging assembly according to claim 27, wherein the outside surface of the optical element that is placed in the hole is coated with black coating to absorb light and prevent glare.
 29. An omni-directional imaging assembly according to claim 26, wherein the surface of the hole is coated with black coating to absorb light and prevent glare.
 30. An omni-directional imaging assembly according to claim 26, wherein the hole is cylindrical in shape.
 31. An omni-directional imaging assembly according to claim 26, wherein the hole is conical in shape.
 32. An omni-directional imaging assembly according to claim 1, further comprising cylindrical slots in the body of the omni-directional lens around the axis of symmetry, said slots formed in size and angle such as to not interfere with the optical path of rays originating in scenes that should be covered by said omni-directional lens; wherein said slots absorb light and prevent glare.
 33. An omni-directional imaging assembly according to claim 1, further comprising a prism and an illumination source; wherein said prism is located coaxially with the omni-directional lens and said illumination source is located to the side of said prism and directed towards said prism; wherein said prism is designed and positioned such as to transmit rays that arrive from the direction of said omni-directional lens to the desired location and to refract illumination rays originating at said illumination source towards said omni-directional lens.
 34. An omni-directional imaging assembly according to claim 9, further comprising an image capture device located above and adjacent to said upper surface, directed opposite to the omni-directional lens, said image capture device being designed to cover an additional scene, at least partially different from the first scene.
 35. An omni-directional imaging assembly according to claim 1, wherein the omni-directional lens further comprises a hole to the side of the vertical axis of symmetry, said hole extending from the upper surface to the lower surface of said lens; wherein said hole comprises a mechanical channel.
 36. An omni-directional imaging assembly according to claim 35, wherein the mechanical channel is used to pass gases, liquids, or mechanical devices through said mechanical channel for cleaning the exterior of the omni-directional lens.
 37. An omni-directional imaging assembly according to claim 35, wherein the mechanical channel is used to pass surgical instruments through the omni-directional lens. 